Crease resistant cellulosic textile material

ABSTRACT

Cellulosic textiles are rendered crease resistant with an impregnant formed by reaction of urea and formaldehyde at first in an acid medium and then with the addition of further urea and also glyoxal in a substantially neutral medium.

United States Patent Petersen et a1.

[4 1 Dec. 30, 1975 CREASE RESISTANT CELLULOSIC TEXTILE MATERIAL Inventors: Harro Petersen, Frankenthal; Klaus Erhardt, Ludwigshafen; Wilhelm Ruemens; Heinz Bille, both of Limburgerhof; Giienter Reuss, Ludwigshafen, all of Germany Assignee: Badische Anilin- & Soda-Fabrik Aktiengesellschaft, Ludwigshafen (Rhine), Germany Filed: Dec. 13, 1972 Appl. No.: 314,800

Published under the Trial Voluntary Protest Program on January 28, 1975 as document n0. B 314,800.

Foreign Application Priority Data Dec. 22, 1971 Germany 2163853 US. Cl. 428/278; 428/272; 428/524; 428/526 [51] Int. Cl. D06M 13/00 [58] Field of Search ll7/l39.4, 143 A, 139.5 A, 117/145; 260/29.4 R; 428/272, 278, 524, 526

Primary Examiner-William D. Martin Assistant ExaminerTheodore G. Davis Attorney, Agent, or FirmJohnston, Keil, Thompson & Shurtleff [57] ABSTRACT Cellulosic textiles are rendered crease resistant with an impregnant formed by reaction of urea and formaldehyde at first in an acid medium and then with the addition of further urea and also glyoxal in a substantially neutral medium.

1 Claim, No Drawings CREASE RESISTANT CELLULOSIC TEXTILE MATERIAL P The invention relates to a process for the produc'tion of crease resist finishes for cellulosic textile material which are stable in storage.

Methylol and alkoxymethyl compounds of acyclic and cyclic ureas and also melamines and carbamates are conventionally used for crease resist finishing. The methylol and alkoxymethyl compounds of urea are preferred for finishing cellulosic textiles. These have only a fairly short shelf life in the form of solutions.

It is known that the shelf life of such solutions can be improved by adding glyoxal, but textiles finished therewith especially with solutions which have been stored for a long time have a fairly hard handle and the resistance to hydrolysis and consequently the durability of the finish to washing are not satisfactory. Moreover the reactivity of the resin declines as the glyoxal content is increased.

It is an object of the invention to improve shelf life without decreasing the reactivity of such liquid textile finishes.

Other objects are to avoid hardening of the handle of the finished textiles and to improve the durability of the finish to washing.

We have found a process for the production of liquid finished for cellulosic textiles having a long shelf life which comprises neutralizing to a pH of from 6 to 7.5 a reaction mixture obtainable by reaction of 1 mole of urea with from 3 to moles of formaldehyde in aqueous solution at a pH of from 3 to 0 and then adding such amounts of urea and glyoxal at a temperature of from to 70C that a total molar ratio of ureazfovmaldehydezglyoxal of 111.5 to :01 to 0.5 is obtained.

For the first reaction in acid solution urea may be used in solid form or as a solution and formaldehyde may be used in solution or in the form of pure polymers as for example paraformaldehyde, trioxane or tetraoxane or also in the form of pure acetals. Urea is reacted with formaldehyde in a molar ratio of from 1:3 to 1:10, preferably in a molar ratio of from 1:4 to 1:6, in the presence of a strong inorganic or organic acid at a pH of from 3 to O to form a precondensate containing urone. This condensation may be carried out advantageously at a temperature of from 60 to 100C.

lnstead of urea it is also possible to react methylenediurea or polymethylenureas or their methylol compounds with formaldehyde to form urone-containing precondensates. Methylolation mixtures of urea with formaldehyde, which in addition to free formaldehyde contain the higher methylol compounds of urea, i.e., trimethylolurea and tetramethylolurea, may also be used as starting materials for the production of the urone-containing precondensates.

Inorganic acids, as for example hydrochloric acid, sulfuric acid and phosphoric acid, and also strong organic acids, as for example p-toluenesulfonic acid, oxalic acid and phthalic acid are suitable as acid catal sts. The reaction in the first stage may be carried out by adding an acid to the mixture of the abovementioned starting materials with formaldehyde and then heating the whole to the desired condensation temperature. It is also possible however to first heat the mixture of starting materials with formaldehyde or a derivative thereof to the condensation temperature and only then to add the acid. According to a preferred embodiment formaldehyde is mixed with the acid and heated to the desired condensation temperature. Urea or the abovementioned starting products are then introduced into this solution. In all embodiments it is also possible to use mixtures of the starting components. The reaction period depends on the temperature and the amount of acid. In the pH range from 2.0 to 2.5 the reaction period at from 90 to 100C for example is about thirty minutes. At a pH of about 1 the reaction period may be shortened to about one minute.

The present invention is based on the surprising discovery that on the basis of the precondensate thus obtained, which still contains free formaldehyde, it is possible by further reaction with urea in the presence of small amounts of glyoxal to obtain liquid finishing agents which have an adequate reactivity and at the same time a long shelf life and which yield finished textiles with a soft handle as well as a good durability of the finish to washing. The precondensates obtained in the manner described are reacted for this purpose with amounts of urea and glyoxal so that a total ratio of ureazformaldehyde:glyoxal of 1:15 to 2.5:0.l to 0.5, preferably of 121.75 to 23:02 to 0.5 is obtained. The

. glyoxal is conveniently added in aqueous solution and the urea in the same form or in crystalline form. Reaction is carried out in the pH range from 6 to 7.5, preferably from 6.5 to 7.2, at a temperature of from 20 to C, preferably at from 30 to 50 C. The reaction period depends on the temperature and pH and is within the range from one hour to five hours. The course of the reaction may be followed for example by quantitative determination of the free formaldehyde in the solution.

The pH may be measured by various methods and the result is not wholly independent of the method used. Our references to pH refer to measurements by means of a glass electrode.

Finishing agents prepared by the process of the invention may if desired be evaporated to about to percent solutions.

The liquid finishing agents are of excellent stability in storage. When stored at temperatures below 25C they remain usable for at least six' months. This couldmot have been foreseen.

The new finishing agents are used in the conventional ways and preferably in the form of an aqueous impregnating liquor to which catalysts required for crosslinking are generally added, Potentially acid catalysts which are generally known'and used for the purpose of textile finishing are suitable for the purpose. Examples are ammonium salts of strong acids, magnesium chloride, zinc chloride and zinc 'nitrate. Mixtures of two or more catalysts may also be used. The concentration-of finishing agent depends on the desired effect. It is generally within the range from 50 to 200 grams per liter. The material to be treated is impregnated with the liquor in the usual way. It is preferred to use a padding machine. The impregnated material is freed from excess impregnating liquor by a conventional method, for example by squeezing. The impregnated fibrous material may be dried more or less completely and then heated in the presence of the acid or potentially acid catalyst at a temperature of from to 210C, preferably from to 180C. The reaction is generally over in from 1 minute to 6 minutes under these conditions. The fibrous material may be mechanically shaped during drying or thereafter, for example by compression,

crimping ironing, calendering, embossing or pleating.

Cellulosic textiles finished in this way have permanent resistance to creasing and crushing, and embossed effects and folds are fairly washproof.

Nitrogenous hydroxymethyl or alkoxymethyl compounds hitherto used and also nitrogen-free finishing agents may be used together with the new finishing agents. It is also possible to use conventional water-repellent, softening, leveling, wetting and finishing agents such as particularly polymer solutions or dispersions. Water repellents include for example paraffin wax emulsions containing aluminum or zirconium salts and also preparations containing silicon and perfluorinated aliphatic compounds. Softening agents include oxyethylation products of higher fatty acids, fatty alcohols or fatty acid amides, high molecular weight polyglycol ethers, higher fatty alcohol sulfonates, N-stearyl- N,N'-ethylidenurea and stearylamidomethylpyridinium chloride. Examples of leveling agents which may be used are water-soluble salts of acid esters of polybasic acids with ethylene oxide or propylene oxide adducts of long-chain oxyalkylatable basic substances. Examples of wetting agents are salts of alkylnaphthalenesulfonic acids, the alkali metal salts of sulfonated dioctyl succinate and the adducts of alkylene oxides -to fatty alcohols, alkylphenols, fatty amines and the like. Examples of finishing agents are cellulose ethers or esters and alginates and also solutions or dispersions of synthetic polymers and polycondensates, for example of polyethylene, polyamides, polyvinyl ethers, polyvinyl alcohols, polyacrylic' acid and esters and amides thereof and corresponding polymethacrylic compounds polyvinyl propionate, polyvinylpyrrolidone, copolymers, for example those of vinyl chloride and acrylic esters, of butadiene and styrene or acrylonitrile, or of u-dichloroethylene and ,B-chloroalkylacrylic esters or vinyl ethyl ether and acrylamide or the amides of crotonic acid or maleic acid or of N-methylolmethacrylamide and other polymerizable compounds. These additional auxiliaries are generally used in amounts of from 0.3 to 4 percent, preferably from 1 to 2.5 percent, based on the weight of the dry textile material; these amounts may be exceeded in exceptional cases.'The following Examples illustrate the invention.

The parts and percentages specified are by weight. Parts by weight bear the same relation to parts by volume as the kilogram to the liter.

The solutions obtained according to Examples 1 to 5 are completely clear even after having been stored for six months or more at room temperature (below 25C) and produce the same results, whereas an aqueous solution containing 35 percent of dimethylolurea deposits solid substance after only one day up to a maximum of fourteen days so that (a) the content of crosslinkable substance is decreased and this is expressed in poorer physical properties and (b) the use of condensed-on constituents occasions a marked change in the handle of the textile material.

EXAMPLE 1 parts of 75percent sulfuric acid are added to 600 parts of 40 percent formaldehyde solution and the mixture heated to 90C. While stirring at 90 to 95C l parts of urea are introduced in a period of from about 20 to minutes. After cooling to 50C within a period of about half an hour, a pH of from 6.6 to 7.0 is set up with concentrated caustic soda solution.

178 parts of percent glyoxal solution are added to this reaction mixture followed by 74 parts of urea. The

4 mixture is stirred for 4 hours at 50C while maintaining a pH offrom 6.6 to 7.0. 996 parts of an aqueous solution' of the finishing agent of the invention is obtained with a solids content of 46 percent. The content of free formaldehyde is 0.7 percent.

EXAMPLE 2 2.5 parts of percent sulfuric acids are added to 720 parts of an aqueous methylolation mixture of urea and formaldehyde in the molar ratio 1:4 with a total content of 40 percent of formaldehyde and 20 percent of urea and the whole is heated at to C for twenty minutes. The pH is 1.0 to 1.1. The reaction mixtures is then cooled to 50C and adjusted to pH 6.5 with concentrated caustic soda solution. The momcontaining precondensate thus obtained has added to it 139.2 parts of 40 percent aqueous glyoxal solution and 144 parts of urea. The mixture is heated for three hours at 45 to 50C at a pH of from 6.8 to 6.9. The solution obtained has a solids content of 58 percent and a content of free formaldehyde of 0.5 percent. The total molar ratio of urea to formaldehyde to glyoxal is l:2:0.2.

EXAMPLE 3 720 parts of the methylolation mixture of urea and formaldehyde used in Example 2 are stirred with 2.5 parts of 75 percent sulfuric acid for thirty minutes at from 95 to 100C and then adjusted to pH 6.8 with concentrated caustic soda solution. 144 parts of urea and 278.4 parts of 40 percent glyoxal solution are added to this precondensate. After heating for 4 hours at 50C at a pH of 6.8 to 6.9, a finishing agent is obtained with a solids content of 58 percent and a content of free formaldehyde of 0.4 percent. The total molar ratio of urea to formaldehyde to glyoxal is 11210.4.

EXAMPLE 4 750 parts of the methylolation mixture used in Examples 2 to 3 are heated with 10 parts of 75 percent sulfuric acid for ten minutes at pH 0.8 at refluxing temperature and then neutralized to pH 7 with concentrated caustic soda solution at 50C. 279 parts of 40 glyoxal solution and l 15 parts of urea are added to the momcontaining precondensate formed. The reaction mixture is stirred for 1 hour at 30C at a pH of from 6 to 6.5 and for another 3 hours at 50C after the pH has been adjusted to 6.8. A finishing agent is obtained having a solids content of 55 percent and a content of free formaldehyde of 0.6 percent. The total molar ration urea:- formaldehydezglyoxal is 1:2.25:0.435.

EXAMPLE 5 750 parts of 40 percent formaldehyde solution are mixed with 5 parts of concentrated hydrochloric acid and parts of urea and the mixture heated for twenty minutes at 90C while stirring. After only a short time deposition of polycondensates takes place but these go into solution again. The whole is cooled to 45C and adjusted to pH from 6.5 to 6.8 with caustic soda solution. 174 parts of 40 percent glyoxal solution and 90 parts of urea are added to the reaction mixture. The reaction mixture is then heated for four hours at a pH of 6.8. The solution obtained has a solids content of 50 percent and a content of free formaldehyde of 0.9 percent. The total molar ratio urea:formaldehyde:- glyoxal is 1:2.5:0.3.

EXAMPLE 6 A bleached and mercerized cotton cloth (l20 g/m is impregnated on a padding machine with a finishing liquor which contains per liter 165 parts of the product UTC Ex4 DMU dry crease angle according to warp l l 10 65 DlN 53,890 weft I 105 60 Monsanto rating after one washing 4.0 3.8 L5 at 60C (cf. AATCC Technical Manual 88A l964T) Loss in tear resistance 27% 29% EXAMPLE Unbleached rayon staple cloth (140 g/m is impregnated on a padding machine with a finishing liquor which contains per liter 230 parts of the product prepared according to Example 4 and 35 parts of a 30 percent solution of zinc nitrate. The wet pickup is percent. The cloth is dried for 4 minutes and condensed at 150C. A comparative experiment is carried out with a freshly prepared liquor from 130 parts of dimethylolurea and 35 parts of a solution of zinc nitrate per liter.

The results are shown in the following Table in which the same abbreviations are used:

Ex4 DMU UTC Dry crease angle according l 12 1 I0 55 to DIN 53,890 32% I07 110 45 Monsanto rating after one washing 5.0 4.75 1.75

at 60C We claim:

1. A cellulosic textile material which has been impregnated with an agent for imparting crease resist to said textile material, said agent comprising an amino resin prepared by reacting 1 mole of urea with from 3 to 10 moles of formaldehyde in aqueous solution at a pH of from 3 to 0, neutralizing said solution to a pH of from 6 to 7.5 and at a temperature of from 20 to 70C adding urea and glyoxal in such amounts that the resulting total molar ratio of urea:formaldehyde:glyoxal is 1:15 to 2.5201 to 0.5, said resin having been cured in the presence of an acid or potentially acid catalyst at a temperature of from to 210C. 

1. A CELLULOSIC TEXTILE MATERIAL WHICH HAS BEEN IMPREGNATED WITH AN AGENT FOR IMPARTING CREASE RESIST TO SAID TEXTILE MATERIAL, SAID AGENT COMPRISING AN AMINO RESIN PREPARED BY REACTING 1 MOLE OF UREA WITH FROM 3 TO 10 MOLES OF FORMALDEHYDE IN AQUEOUS SOLUTION AT A PH OF FROM 3 TO 0, NEUTRALIZING SAID SOLUTION TO A PH OF FROM 6 TO 7.5 AND AT A TEMPERATURE OF FROM 20* TO 70*C ADDING UREA AND GLYOXAL IN SUCH AMOUNTS THAT THE RESULTING TOTAL MOLAR RATIO OF UREA:FORMALDEHYDE:GLYOXAL IS 1:1.5 TO 2.5:0.1 TO 0.5, SAID RESIN HAVING BEEN CURED IN THE PRESENCE OF AN ACID OR POTENTIALLY ACID CATALYST AT A TEMPERATURE OF FROM 100* TO 210*C. 